Selective treatment of endocardial/myocardial boundary

ABSTRACT

A method for treating myocardium using at least one mechanical or electromagnetic energy functional device for forming a network of branched, interconnecting passages in a boundary between endocardium and myocardium, thereby enhancing blood flow into the treated zone, and a device for selectively treating ischemic myocardium tissue comprising a tube having proximal end and distal end, and at least one hollow lumen and defining an axis, at least two mechanical or electromagnetic energy functional devices disposed within the tube, the at least two mechanical or electromagnetic energy functional devices each having a distal end disposed adjacent the distal end of the central tube, and a deflecting member adjacent the distal portion of the central tube for deflecting the distal end of each of the at least two mechanical or electromagnetic energy functional devices away from the axis, for enabling treatment of selective areas of ischemic or hibernating myocardium tissue.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.08/978,036, entitled “SELECTIVE TREATMENT OF ENDOCARDIAL/MYOCARDIALBOUNDARY,” filed Nov. 25, 1997 now U.S. Pat. No. 6,156,029.

FIELD OF THE INVENTION

The present invention relates generally to interventional devices formedical procedures. More particularly, the invention relates toselective treatment of ischemic or infarcted myocardium, with mechanicaland electromagnetic energy functional devices, for simulating extensionof the boundary between myocardial and endocardial layers within theheart. The invention is particularly adapted for simulating extension ofthe endocardial layer into the myocardium and for treating hibernatingtissue zones.

BACKGROUND OF THE INVENTION

Transmyocardial Revascularization

In the treatment of heart disease, one method of improving myocardialblood supply is called transmyocardial revascularization (TMR), thecreation of channels in the myocardium of the heart. The procedure usingneedles in a form of surgical “myocardial acupuncture” has been usedclinically since the 1960s. Deckelbaum. L. I., CardiovascularApplications of Laser Technology, Lasers in Surgery and Medicine15:315-341 (1994). The technique relieves ischemia by causingangiogenesis and allowing blood to pass from the ventricle through thechannels either directly into other vessels communicating with thechannels or into myocardial sinusoids which connect to the myocardialmicrocirculation.

In the reptilian heart, perfusion of the myocardium occurs viacommunicating channels between the left ventricle and the coronaryarteries. Frazier, O. H., Myocardial Revascularization withLaser—Preliminary Findings, Circulation, 1995; 92 [supplII]:II-58-II-65. There is evidence of these communicating channels inthe developing human embryo. In the human heart, myocardial microanatomyinvolves the presence of myocardial sinusoids. These sinusoidalcommunications vary in size and structure, but represent a network ofdirect arterial-luminal, arterial-arterial, arterial-venous, andvenous-luminal connections. This vascular mesh forms an important sourceof myocardial blood supply in reptiles but its role in humans is poorlyunderstood.

This is confirmed by recent research and a recent article. A greaterproportion of reptilian endocardium and myocardium is supplied withoxygenated blood from the left ventricle itself, as opposed to thecoronary arteries. Reptilian endocardium is relatively thickerandmore-sponge-like than human myocardium, deriving from the extensivenetwork of sinusoids and large channels emanating from the leftventricle and richly innervating the myocardium, thereby providing anincreased effective surface area for blood flow, also known as“washing”, and transfer of oxygen and nutrients to the myocardium. Inthe research protocol, after explanation and instrumentation, alligatorhearts were perfused via the coronary arteries as well as via “washing”from the left ventricle. Using microspheres to estimate myocardialperfusion in the beating hearts, it was shown that although theepicardium was well perfused by the coronary arteries, a significantproportion of endocardial perfusion was from the ventricular chamberrather than the coronary arteries. Kohmoto, T. et al, Assessment ofTransmyocardial Perfusion in Alligator Hearts, Circulation, Vol. 95, No.6, Mar. 18, 1997.

Apparatus and methods for extending the thickness of endocardial tissue,and increasing oxygen and nutrient transport by washing of blood throughthe left ventricle, are virtually unknown. Conventionally, a processcalled transmyocardial revascularization is directed to forming adiscrete number of spaced-apart channels, surgically from an epicardialsurface through epicardium (TMR) or percutaneously through the leftventricle directly into myocardial tissue (PTMR). However, conventionalTMR/PTMR does not create a dense pattern of stimulus injuries placed tosimulate extension of the porous endocardium. TMR also does not focustreatment on the endocardial/myocardial boundary regions whereventricular washing flow via endocardium can enhance angiogenesis.Furthermore, treating hidden zones of hibernating, infarct-damaged orother types of tissue with a denser pattern of stimulation pathways isdesirable and may be accomplished using the apparatus and methods forselective treatment of the endocardial/myocardial boundary.

ADVANTAGES AND SUMMARY OF THE INVENTION

Thus, it is an advantage of the present invention to provide anapparatus and method of use for selective myocardial revascularization,which overcomes the limitations of the prior art.

It is another advantage of the present invention to provide an apparatusand method especially adapted for selective treatment of hibernatingtissue, infarct-damaged or other types of tissue best treatedselectively.

It is a further advantage of the present invention to provide anapparatus with one or more fiber optic laser delivery means foreffecting selective treatment of the endocardial/myocardial boundary.

It is a further advantage of the present invention to provide a catheterapparatus for placement within a heart chamber, organ aperture or otherbody opening, the apparatus having at least one lumen for guiding anenergy delivery device or mechanical device to selected surfaces of theheart, heart chamber, organ aperture or other body opening for treatmentthereon, particularly adapted for selective treatment of theendocardial/myocardial boundary.

Yet an additional advantage and object of the present invention is toprovide a multiple channel type surgical or minimally invasive surgicalapparatus for percutaneous, surgical or minimally invasive surgical usefor creation of a plurality of stimulation zones or myocardial channelsco-extending from a single epicardial, myocardial or endocardial pointor position.

Another advantage and object of the present invention is to provide asurgical apparatus for performing selective treatment from an epicardialsurface.

It is a further advantage of the present invention to provide anoptimized amount of trauma or means of injury specific to or within aboundary, such as between endocardium and myocardium, or between infarctand non-infarct boundaries, naturally provided with ventricular bloodvia the highly vascularized endocardium.

Another advantage of the present invention is to treat boundary regionsby minimizing or otherwise preventing undesirable and unnecessary lasingor other mechanical damage to existing endocardium, or epicardium, togain access to the boundary region by piercing through the endocardiumor epicardium to a depth which allows creation of the injury only at theselected boundary region.

In summary, the present invention is an apparatus for placement within aheart chamber, organ aperture, chest cavity or other body opening. Theapparatus has at least one lumen for guiding an energy delivery deviceor mechanical device to selected surfaces of a heart or heart chamberfor treatment thereon. The distal tip of the device has one or morefunctional devices extending therefrom, optionally having a deflectioncontrol mechanism therein. The apparatus can be used in conjunction witha fiber optic or other laser delivery means, mechanical interventionmeans, radio frequency device, microwave device, ultrasound device orfluid jets.

In a preferred embodiment, the invention comprises a transluminalcatheter having a proximal end and a distal end and at least one lumenwith a handle portion at the proximal end and a treatment devicedeflecting mechanism, such as a ball or cone, at the distal end. One ormore, preferably several, treatment devices can be advanced out thedistal end of the lumen, and deflected by the ball or cone at an angleto provide a relatively dense multiple pattern of treatment points fromadjacent a single site. By forming a large number of mechanical orenergy incisions through the endocardium and in myocardium, i.e. in theendocardial/myocardial boundary, the treated myocardial area will haveendocardium-like properties, including providing a greater surface areaand higher efficiency of oxygen and nutrient transfer via blood washingof the untreated myocardium through the intact and densely profusedendocardium which receives a large amount of oxygenated blood via theventricle.

In a preferred embodiment, the invention is a surgical and minimallyinvasive surgical handpiece with advancement mechanism to allowinsertion of an energy or mechanical device through the epicardialsurface to a desired depth where deployment of multiple treatmentdevices can occur to create a relatively dense pattern of injury inseveral millimeters of myocardium adjacent a border with endocardium andinto the endocardium.

A novel method of locating and treating zones of myocardial tissue, suchas adjacent a boundary, which have been damaged by infarct or otherwiseis also disclosed using described apparatus. Such hidden or hibernatingzones are treatable by extending individual optical fibers or fiberbundles therein, so as to effectively create a dense pattern of injuryfrom the ventricle through healthy endocardial tissue, or from theepicardium, into the hibernating zones. The method treats boundaryregions by minimizing or otherwise preventing undesirable andunnecessary lasing or other mechanical damage to existing endocardium togain access to the boundary region. Piercing tools are described tofacilitate advancement to the selected boundary prior to creation of theinjury.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative section view of cardiac tissue, includingendocardium, epicardium, myocardium and a typically central,hibernating, infarct damaged zone of myocardial tissue.

FIG. 2A is a representative perspective view of a preferred embodimentof a selective treatment of the endocardial/myocardial boundary system100 of the present invention.

FIG. 2B is a representative detail view of the preferred embodimentshown in FIG. 2A taken along lines 2B—2B.

FIG. 2C is a representative perspective view of another preferredembodiment of a selective treatment of the endocardial/myocardialboundary system 150 of the present invention.

FIG. 2D is a representative detail view of the preferred embodimentshown in FIG. 2C taken along lines 2D—2D.

FIGS. 3A-3E are representative perspective views of a preferredembodiment of the apparatus and method of selective treatment of theendocardial/myocardial boundary shown in FIGS. 2A and 2B.

FIG. 3F is a representative section drawing of the treated area asformed by the apparatus and methods of the present invention.

FIGS. 4A and 4B are representative isometric and section views,respectively, of a preferred embodiment of a selective treatment of theendocardial/myocardial boundary system 300 of the present invention.

FIG. 4C is a representative view of another preferred embodiment of aselective treatment of the endocardial/myocardial boundary system 350 ofthe present invention.

FIG. 5A is a representative section view of a preferred embodiment of aselective treatment of the endocardial/myocardial boundary system 400 ofthe present invention.

FIG. 5B is a representative section view of another preferred embodimentof a selective treatment of the endocardial/myocardial boundary system450 of the present invention.

FIGS. 6A and 6B are representative cross sectional and section views,respectively, of another preferred embodiment of a selective treatmentof the endocardial/myocardial boundary system 500 of the presentinvention.

FIG. 7A is an isometric view of an apparatus for forming branched,contiguous, multi-channeled, sinusoidal and interconnected treatmentzones for selective treatment of endocardial/myocardial boundary.

FIG. 7B is representative view of a branched, contiguous,multi-channeled, sinusoidal and interconnected treatment zone.

FIG. 8 is a representative section view of rotating mechanical drilltype apparatus 700 for forming sinusoidal and interconnected channels ortreatment zones in endocardial/myocardial boundary.

FIG. 9 is a representative section view of resistance type heating tipapparatus 750 for forming sinusoidal and interconnected channels ortreatment zones in endocardial/myocardial boundary.

FIG. 10 is a representative section view of fluid jet nozzle apparatus780 for forming sinusoidal and interconnected channels or treatmentzones in endocardial/myocardial boundary.

FIG. 11 is a representative section view of radio frequency apparatus800 for forming sinusoidal and interconnected channels or treatmentzones in endocardial/myocardial boundary.

FIGS. 12A, 12B and 12C are representative isometric and section views ofthe distal end and steering system of a preferred embodiment of acatheter ultrasound guidance system 300′ for forming sinusoidal andinterconnected channels or treatment zones in endocardial/myocardialboundary.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

It will be understood that while numerous preferred embodiments of thepresent invention are presented herein, many of the individual elementsand functional aspects of the embodiments are similar. Therefore, itwill be understood that structural elements of the numerous apparatusdisclosed herein having similar or identical function will have likereference numerals associated therewith. All of the devices disclosedand described herein are suitable for selective treatment of ischemictissue. The devices may be used to treat myocardium borderingendocardium so that the treated area simulates endocardium physicallyand in function, thereby resulting in “endocardial extension”. The samedevices may be used to selectively treat other areas of heart tissue,particularly hibernating myocardium.

FIG. 1 is a representative section view of cardiac tissue, includingendocardium E, epicardium P and a typically central, hibernating,infarct damaged zone of tissue Z surrounded by conventional myocardiumM. Zones of tissue Z which are oxygen or nutrient starved are generallydenser and can be located via an angiogram or felt by the gloved fingerof a physician performing an exploration. Such damaged zones may be theresult of an infarction, damaging arrhythmia, other physical, chemicalor electrical assault or event, etc. In TMR type treatments, thesehibernating zones can be treated by mechanically piercing or channelingusing sharpened needles and blades, mechanical drills and/or energydelivery devices, such a lasers, radio frequency devices, microwaveenergy, ultrasound energy, and fluid jets.

The treatment differs from conventional TMR or PTMR in several importantways. For example, as compared to TMR or PIMP, fewer or notrans-myocardial channels are created. In “endocardial extension” orselective treatment of the endocardial/myocardial boundary, theendocardial/myocardial boundary is treated using a denser pattern ofsmall laser or mechanical or otherwise created injury sites, i.e. sitesfor angiogenesis and/or stimulation zones, adjacent to the healthyendocardium. These injuries are specifically located adjacent one of thebest natural, localized sources of oxygenated blood, i.e. the leftventricle and endocardium. Treatment also is designed to selectivelytreat myocardium by simulating conversion of the inner-most severalmillimeters of myocardium into tissue similar to adjacent endocardium,having decreased density resulting from a relatively dense stimulationzone or injury pattern. It will be understood that although theapparatus and methods of the present invention are described with agreat deal of particularity, selective treatment of theendocardial/myocardial boundary treatment may be done generally fromeither endocardial or epicardial surfaces, both of which procedures areincluded within the scope of the present invention. Also, selectivetreatment of hibernating tissue is performed using same or similar densetreatment patterns of pathways, interconnected physically and througheffects and results of angiogenesis.

FIG. 2A is a representative perspective view of a preferred embodimentof a selective treatment of the endocardial/myocardial boundary system100 of the present invention. FIG. 2B is a representative detail view ofthe preferred embodiment shown in FIG. 2A taken along lines 2B—2B. Amain, outer tube 102 has at least one large lumen 104 extendingtherethrough. A plurality of mechanical or electromagnetic, such asoptical fibers, or fiber bundles, or other functional devices 106 extendthrough the large lumen 104, from the proximal end 108 to the distal end110. Appropriate blood seal means 112 will be known to those skilled inthe art.

Additionally, a control tether 114 extends between the proximal end 108of the apparatus, therethrough to the distal end 110 where it is coupledto a deflecting member 116. The tether 114 can run through the centrallumen 104 in communication with the plurality of mechanical orelectromagnetic functional devices 106 or the tether can be placedthrough an independent tether lumen 130 as shown in FIG. 2D. Either inconstruction or operation, as the plurality of mechanical orelectromagnetic functional devices 106 are extended axially through thecentral lumen 104 and out the distal end 110 they are deflected from theaxis in an outwardly splayed configuration. In the preferred embodimentshown, the deflecting member 116 can be controlled independently bymanipulation of a handle portion 118 at the proximal end 120 of tether114. Thus, the distal ends 122 of the plurality of mechanical orelectromagnetic functional devices 106 can be controllably spaced intoan operable and advantageous configuration to simultaneously orsequentially form a relatively dense pattern of pathways.

FIG. 2C is a representative perspective view of another preferredembodiment of a selective treatment of the endocardial/myocardialboundary system 150 of the present invention. FIG. 2D is arepresentative detail view of the preferred embodiment shown in FIG. 2Ctaken along lines 2D—2D. The central tube 102′ can have any operable oradvantageous number of elongated lumens 104′ extending therethrough, andis preferably formed as an extrusion or molding. The trifurcatedproximal end 108′ has a plurality of blood seal means 112′ and aplurality of mechanical or electromagnetic functional devices 106 enterthe apparatus 150 therefrom. Tether 114 extends through an independenttether lumen 130′ as well.

It will be understood that the plurality of mechanical orelectromagnetic functional devices 106 can be any number of individualfibers, bundled or separated, and optical fiber devices which would beknown to those skilled in the art would contain individual fibers with arange of diameters, such as anywhere between about 1000 microns to about25 microns. As shown in FIGS. 2A and 2B, individual fibers can runcommingled through the central lumen 104 and then be separated into two,three or more discrete fibers or bundles near the distal end 110 of theapparatus, and they can also be divided into separate bundles throughoutthe length of the apparatus 150. Furthermore, the portions of fibersextending past the distal end 110 or 110′ and being deflected bydeflecting member 116 can be wrapped clusters of fibers, individualfibers, etc. Fibers selected and sized at 100μ or less may be used topierce to the desired depth for injury creation with or withoutsharpening or addition of a separate piercing mechanism.

FIGS. 3A-3E are representative perspective views of a preferredembodiment of the apparatus and method of selective treatment of theendocardial/myocardial boundary shown in FIGS. 2A and 2B. It will beunderstood that the system 100 shown can be introduced into the leftventricle 250 through a E10 separate guiding catheter or over a separateguide wire, etc., which are not shown. The apparatus can also be used orbe adapted for use surgically or in minimally invasive surgicalprocedures.

Introduced percutaneously into the left ventricle 250, the distal end110 of the apparatus 100 can be positioned as desired as shown in FIG.3A. Control of tether 114 will allow the operator or physician toadvance the deflecting member 116 in the direction A as shown in FIG.3B. As the plurality of mechanical or electromagnetic functional devices106 pass through the distal end 110 of the apparatus 110, the distalends 122 will be deflected away from each other, about deflecting member116. It will be understood that once the deflecting member 116 is spacedas desired from the distal end 110 of the central tube 102, it can beplaced directly on an endocardial surface 252 and the plurality ofmechanical or electromagnetic functional devices 106 can be extendedover the deflecting member 116 and into myocardium through endocardium.Alternatively, the plurality of mechanical or electromagnetic functionaldevices 106 can be extended over the deflecting member 116 and theentire distal end 110 of the apparatus can be extended so that thedistal ends 122 pierce endocardium and penetrate myocardium, and thedeflecting member 116 then comes to rest upon an endocardial surface252. In the second instance, the deflecting member 116 acts as a depthstop, delimiting and otherwise preventing excessive or undesiredadvancement of the functional devices 106 into tissue.

FIG. 3D shows retraction of the deflecting member 116, such as bycontrol of tether 114, thereby causing movement of deflecting member 116in a direction shown as B, and deflection of the distal ends 122 of theplurality of optical fibers, fiber bundles or other functional devicesaway from each other, or splayed out in direction C. Thus, as will beunderstood, further retraction of tether 114 relative to the functionaldevices 116 will cause continued or further splaying, deflection andseparation of the distal ends 122 of the functional devices 116.

FIG. 3E shows a preferred embodiment of the apparatus 100 as shown inFIG. 2A in which the main outer tube 102 2has been angulated. Uponcontinued retraction of control tether 114 past the point at which thedeflecting member 116 is at its maximum retraction, a secondarydeflection occurs at notched portion 280 which collapses, therebydeflecting the distal end 110 of the apparatus 110 to a differentportion of endocardial surface 252. Furthermore, rotation of apparatus100, such as in direction R as shown, will position the distal end 110into a plurality of different positions for extending endocardium. Itwill be understood by the foregoing that the notched portion 280 isoptional and provides an additional degree of freedom for control.Substituting more traditional tensioning wire tip deflection systems, ascommonly used in electrophysiology, would be an alternative and knownapparatus for implementing “endocardial extension”. The secondaryangulation at one or more points along the outer tube 102 providesadditional angulation control, specifically in catheter applications andsurgical procedures involving an approach from lateral and posteriorsurfaces.

FIG. 3F is a representative section drawing of the treated area El asformed by the apparatus and methods of the present invention. Adjacentthe endocardial surface 252 there is the transitory zone 254 betweenendocardium E and myocardium M. On the opposite side of the tissue isthe epicardial surface 256, epicardium P and the boundary 258 betweenthe epicardium P and myocardium M. Upon formation of a plurality ofinjuries, piercing or zones of stimulation C, a new boundary 260 isformed in what was formerly conventional myocardium M and defining a newboundary E′ between extended endocardium and conventional myocardiumThus, as shown diagrammatically, the original endocardium E becomes“extended” with communicating sinusoidal channels with enhanced bloodwash and flow into the extended endocardium area E′ thereby enhancingblood flow deeper into the myocardium by forming greater surface area ofexchange at new boundary 260. It will be noted that performing thedescribed “endocardial extension” is important and valuable because itsupplements supply from the coronary arteries which generally supplymost of the myocardium with oxygenated blood. In almost all cases ofcoronary disease, however, this function of the coronary arteries isessentially impaired.

FIGS. 4A and 4B are representative isometric and section views,respectively, of a preferred embodiment of a selective treatment of theendocardial/myocardial boundary system 300 of the present invention. Inthis embodiment, the deflecting member 316 is integral and internal tothe distal end 110 of central tube 302. The deflecting member 316 can bea section located at the distal end 110 only, or the central tube 302can be formed as an extrusion with three or more or less distinct andseparate channels running through the tube 302 and effectivelydeflecting or splaying the distal ends of the functional devices 106away from each other.

FIG. 4C is a representative view of another preferred embodiment of aselective treatment of the endocardial/myocardial boundary system 350 ofthe present invention. In this embodiment, the deflecting member 316 iscone shaped. Upon extension of mechanical or electromagnetic functionaldevices 106 through the central tube 302, the distal tips 122 aredeflected or splayed away from each other, creating a tool sufficientfor forming a plurality of laser or mechanically created injuries,pierce or stimulation zones in endocardial tissue. It will be understoodthat the precise shape of deflecting member 316 can be varied, but willpreferably cause little undesired friction between the distal ends 122of the mechanical or electromagnetic functional devices 106 and thedeflecting member 316. Additionally, control tether 314 can be fixed orpermanent, thus providing optional independent control of deflectingmember 316.

It will be understood from the foregoing, therefore, that the deflectingmember can have a plurality of different sizes, shapes andconfigurations. To expand and clarify, the deflecting member 116 portioncan be movable or retractable, such as mounted on a tether 114 as shownin FIGS. 2A, 2C, 3A-3E, etc. The deflecting member 116 can also be fixedin place with regard to the outer tube 102, and can comprise a discretenumber of deflecting ramps, grooves, slots, or guide channels.Additionally, the deflecting member 116 can be located well within thedistal end of the outer tube 102, just inside or outside of the distalend 110 of the outer tube, or it can be located a short distance beyondthe distal end 110 of the outer tube 102.

FIG. 5A is a representative section view of a preferred embodiment of aselective treatment of the endocardial/myocardial boundary system 400 ofthe present invention. FIG. 5B is a representative section view ofanother preferred embodiment of a selective treatment of theendocardial/myocardial boundary system 450 of the present invention. Ineach of these embodiments, the mechanical or electromagnetic functionaldevices 106 are disposed either fixedly or movably, such as by advanceor retraction, within hollow lumens within the central tube 402.

In the embodiment shown in FIG. 5A, the distal ends 122 of themechanical or electromagnetic functional devices 106 are disposedimmediately adjacent small apertures 404 within the distal end 410 ofcentral tube 402. The individual mechanical or electromagneticfunctional devices 106, such as fiber bundles, can be positionedpermanently within the central tube 402 such that laser energy or othertype of energy from the distal tips 122 can reach target tissue, but thedistal tips 122 won't cause unintended or undesired trauma or injury totissue which the apparatus 401 is being advanced into.

A pointed piercing tip 450 can be inserted through endocardium N andinto myocardium M. New treatment area N′ is formed as shown. Thepiercing tip 450 can have any conventional or custom shape or designcharacteristic, including sharpened to a point, blade end, cross-cut,center-radiating multi-blade castings or extrusions, hollow piercingneedle, etc. An optional sensor, such as a conventional pressuretransducer 403, may be placed at the tip 450 to determine peak pressureif use of the treatment device is to be correlated with wall thickness.For instance, laser energy or piercing may occur at maximum pressure toensure maximum tissue penetration in certain boundary areas. Signalsfrom the pressure transducer may be used to enable the laser, andabsence of a maximum signal prevents laser firing.

As shown in FIG. 5B, the apparatus 450 has a blunt tip 452. Themechanical or electromagnetic functional devices 106, such as individualfibers, are shown advanced through individual windows 404 at the distalend 410 of central tube 402. In both embodiments, as mentioned above,the internal lumen or lumens of the central tube 402 encase themechanical or electromagnetic functional devices 106. In a single lumenhollow tube with a plurality of small apertures 404, the fibers wouldall be bundled together. Alternatively, the central tube may have aplurality of different, even differently shaped or organized, hollowinternal lumens such as formed by extrusions, moldings, etc., whichwould provide a plurality of lumens for independently operablemechanical or electromagnetic functional devices 106.

Extension and/or retraction of the distal ends 122 of the mechanical orelectromagnetic functional devices 106 could be before or after bearingthe distal blunt, stabilizing end 452 against an endocardial surface,and it will be understood that the mechanical or electromagneticfunctional devices 106 could be extended or retracted one at a time, orsimultaneously.

The apparatus shown in FIG. 5B is especially suitable for surgical, andespecially minimally invasive surgical use. Tissue can be pierced to adesired, calculated or otherwise determined depth and then mechanical orelectromagnetic energy devices can then be extended through the piercedopening.

FIGS. 6A and 6B are representative cross sectional and section views,respectively, of another preferred embodiment of a selective treatmentof the endocardial/myocardial boundary system 500 of the presentinvention. As an alternative embodiment of the invention to the singlestrand or bundle version previously described, a selective treatment ofthe endocardial/myocardial boundary system 500 may be provided which hasa plurality of spaced apart treatment devices. A selective treatment ofthe endocardial/myocardial boundary system 500 has, for example but notlimited to, four relatively smaller optical fiber strands 502 whichproject outwardly like an axially parallel, spaced apart group of prongsfrom a transverse stop member 504 at the distal end of the selectivetreatment of the endocardial/myocardial boundary system 500. Each ofthese smaller fiber strands 502 has a diameter of around 0.1 to 0.5 mmand its distal tip 506 may be blunt or beveled. The length of theseoptical prong-like strands is roughly the estimated thickness of theendocardium, e.g. 1.5 to 3.0 mm and despite their relatively smalldiameter these prong-like elements are quite rigid. Inwardly from thestop member 504 the smaller fiber strands 502 are preferably heldtogether by suitable potting compound 508 which is surrounded by aplastic sheath 510.

During a selective treatment of the endocardial/myocardial boundaryprocedure using the treatment system 500, the apparatus is pushedagainst the wall of the heart until the distal tips 506 of the spacedapart projecting strands 502 penetrate into myocardium. Alternatively,laser energy may be used to penetrate the wall. As with previousembodiments, laser power is triggered to emit laser energy from thedistal tips of the strands after they are moved forward in increments toform channels or stimulus pockets beyond each distal tip within themyocardium tissue. As laser energy is emitted from the distal end ofeach fiber strand 502, following each interval of penetration, a networkor matrix of interconnected, sinusoidal passages, channels or stimuluspockets is created within the myocardium. In this embodiment, as well asin embodiments showing multiple treatment devices, treatment producesinterstial areas of untreated tissue surrounding by treated areasthereby promoting angiogenesis.

As another approach to selective treatment of the endocardial/myocardialboundary, retro-lasing can be performed. This novel method includes thesteps of advancing the distal tip or tips of laser delivery means suchas mechanical or electromagnetic functional devices a selected distanceinto the myocardium and then delivering laser energy to create aselective treatment of the endocardial/myocardial boundary channel orother treatment site while simultaneously retracting the fiber, laserdelivery means or other functional device. With this procedure, inasmuchas laser energy is only delivered during retraction of the fiber, thepossibility of advancing the fiber too far and lasing through anepicardial surface is reduced, and the risks of complications arisingfrom such epicardial perforations, including but not limited to cardiactamponade (a buildup of pressure in the pericardial sac caused by thepresence of an excess of fluid such as blood), proliferation ofadhesions between the epicardium and the pericardial sac (therebypreventing normal, frictionless enclosure of the heart muscle within thepericardial sac), etc., are minimized.

Furthermore, adjunct use of appropriate drug delivery apparatus, bloodseal means, depth stop apparatus, visualization means, marker means aswell as other hardware and methodology will be considered within thescope of the present invention. Additionally, use of electrophysiology(EP) readings and readings from other sensors positioned at the distaltip 118 for confirming tissue contact, such as with an electrode alongwith or instead of the pressure transducer 403FIG. 5A, temperature,conductivity, density, durometer, porosity, permeability or othermechanical, chemical or electrical characteristic of tissue will beparticularly useful.

The present invention is intended for use with any medical laser. Inparticular, the Holmium or excimer laser is particularly suited to thepresent invention. However, any suitable laser source, pulsed orotherwise, could provide laser energy to the laser delivery means of thepresent invention for performing the method of the present invention.Likewise, the catheter and surgical equipment, including laser deliverymeans, referred to in the present document as well as that known andused in medicine and other disciplines today and in the future, will beincluded in the scope of this disclosure. Such laser delivery meansinclude, but are not limited to, individual optical fibers as well asbundles of fibers with and without piercing tips and with or withoutfiring tips or fiber ends having shaped or contoured end faces forselectively diverging the laser beam or other laser energy divergingmeans, rods, mirrors configurations and other laser delivery means withand without focusing lens and the like. It will also be understood thatthe apparatus and method of the present invention as described hereinincluding the novel combination or use with of any conventionalmechanism or method which are known to those skilled in the art, areincluded within the scope of this invention. Furthermore, with regard tonon-laser selective treatment of the endocardial/myocardial boundary, acannula or trocar assembly may be extended into the tissue of the leftventricle, with or without use of a mechanical piercing tool.

It will further be understood that while the present invention has beendescribed for selective treatment of the endocardial/myocardial boundaryfrom endocardial surfaces in the left ventricle, the apparatus andmethods described herein are equally intended for use in any suitableprocedure, including but not limited to procedures where any device needbe extended through a guide catheter to an opening or other point withinthe body for other medical procedures including laser treatment,visualization, biopsy, etc. “Stimulation”, for example, is performed byusing laser energy to create zones or pockets, optionally interconnectedat least initially by small channels ablated through the tissue, for theintroduction of blood born growth and healing factors and stimulatedcapillary growth surrounding the lased zones or pockets to create anincreased supply of oxygen to the tissue and thus a revitalization ofthe heart muscle. Methods and apparatus for causing stimulation are morefully described in co-pending U.S. patent application Ser. No.08/664,956 filed Jun. 13, 1996 entitled INTRAOPERATIVE MYOCARDIAL DEVICEAND STIMULATION PROCEDURE.

FIG. 7A is an isometric view of an apparatus 600 for forming branched,contiguous, multi channeled, sinusoidal and interconnected treatmentzones for selective treatment of endocardial/myocardial boundary. FIG.7B is a representative view of a branched, contiguous, multichanneled,sinusoidal and interconnected treatment zone. The apparatus is morefully described in U.S. Pat. No. 5,766,698 filed Jul. 3, 1996 entitledCONTIGUOUS, BRANCHED TRANSMYOCARDIAL REVASCULARIZATION (TMR) CHANNEL,METHOD AND DEVICE issued Jun. 16, 1998. Thumb wheel 602 is used toadvance a mechanical or electromagnetic energy functional device 106through the handpiece and out the rotating head section 608. Thedistance which the fiber is advanced is controlled by a laser deliverymeans slider depth adjust means 604. The maximum depth of the injurywhich is to be created by the handpiece can be set precisely andconveniently by locating the side slider at the appropriate axialposition, as indicated by a scale or other reference means 606.

Thus, contiguous, branched injuries 650 which originate at a singlepoint 652 in either endocardium or epicardium 654 develop along aplurality of radiating, ultimately independent paths, through at leastportions of myocardium 656 and into endocardium, to permit capillarycommunication and enhanced myocardial infusion of oxygenated blood,growth, healing, and other factors. Such apparatus is particularlysuitable for surgical procedures, such as in open heart or minimallyinvasive surgery (MIS).

FIG. 8 is a representative section view of rotating mechanical drilltype apparatus 700 for forming sinusoidal and interconnected treatmentzones in the endocardial/myocardial boundary. The apparatus 700 has amounting shaft 702 and a set of cutting teeth 704 spaced around theperimeter of circular spinning sleeve 706. Optionally, an advancable orextendable pointed piercing cone or pyramid shaped tip 708 can be usedin conjunction with the spinning cutting device to pierce tissue to actas an introducer and the piercing tip 708 will part off, penetrateand/or pierce the tissue'easily.

FIG. 9 is a representative section view of resistance type heating tipapparatus 750 for forming treatment zones in endocardial/myocardialboundary. A distal tip 752 is resistively or inductively heated byconductors 754 and 756. The operating temperature of the distal tip 752is sufficient to form channels or cause stimulation of myocardialtissue. A thermocouple or other temperature sensing device 758 may beimbedded into the distal tip 752 to determine the temperature thereof.The signal developed by the sensing device 758 may be used to controlthe electrical power to the distal tip 752 in a conventional manner.

FIG. 10 is a representative section view of fluid jet nozzle apparatus780 for forming sinusoidal and interconnected injury or treatment zonesin endocardial/myocardial boundary. One or more high velocity fluid jets782 are emitted from a discharge tip 784 in the distal end of innertubular member 786 is used to form the channel or stimulation zone.Debris from the channel forming operation is aspirated away from thesite through annular lumen 788 formed between the inner tubular member786 and outer tubular member 790. By directing jets of pressurizedfluids at selected positions within myocardium, tissue can bemechanically disrupted and thereby removed.

FIG. 11 is a representative section view of radio frequency apparatus800 for forming sinusoidal and interconnected injury or treatment zonesin endocardial/myocardial boundary. A method of use includes positioningan array of active electrodes 802 in close proximity to a target site onthe wall of a patient's heart, and applying a high energy, operativefrequency, such as a radio frequency, between the active electrodes 802and a return electrode 804 to ablate tissue at the heart wall. The highfrequency energy ablates, i.e. volumetrically removes the heart tissue,and the electrodes 802 and the distal tip 806 of the apparatus 800, whenthe energy supplied is properly controlled, will bore a plurality ofchannels, pathways or interconnections through the heart tissue. Suchradio frequency apparatus are more fully described in InternationalPublication Number WO 97/18768 published May 29, 1997 entitled SYSTEMSAND METHODS FOR ELECTROSURGICAL MYOCARDIAL REVASCULARIZATION.

FIGS. 12A, 12B and 12C are representative isometric and section views ofthe distal end and steering system of a preferred embodiment of acatheter ultrasound guidance system 300′ for forming treatment zones inendocardial/myocardial boundary. A matching layer 110′, gold trace 106′,transducer crystal 104′, backing 114′, coaxial cable 112′ and housing116′ are assembled together. Mounting face 130′ couples to the distaltip 303′ of catheter 300′. It will be understood by those known in theart that such coupling means includes, and is not limited to, bayonetand other quick connect mounts, screw on or press fit/snap on couplings,etc.

The catheter 300′ is steerable and has steering means as describedherein. A central catheter tube 302′ terminates in the distal tip 303′.A spiral spring member 304′ made of a radiopaque material addsvisibility to the bend radius of the apparatus and enhances steerabilityof the apparatus 300′. A flat planar, rigid shim 306′ couples betweenthe distal tip 303′ of the catheter 300′ and an intermediate sleeve308′. A pull cable 310′ also attaches to the distal tip 303′ oppositethe annular opening 312′ through the distal tip 303′ so as to act uponthe distal tip 303′ and cause deflection of the shim 306′ as desired tosteer the distal tip 303′ to selected regions or surfaces. An outerjacket 314′ protects the catheter assembly 300′. Embodiments of thesteerable catheter apparatus with the ultrasound guidance system aredescribed in U.S. patent application Ser. No. 08/852,977 filed May 7,1997 entitled ULTRASOUND DEVICE FOR AXIAL RANGING and incorporatedherein in its entirety. Embodiments of the steerable catheter apparatusof the present invention without the ultrasound guidance system aredescribed in U.S. patent application Ser. No. 08/833,352 filed Apr. 4,1997 entitled STEERABLE CATHETER and incorporated herein in itsentirety. The device preferably is approximately 7 French and uses afiber bundle 0.5 mm or less in diameter for endocardial extension.

Additionally, the ultrasound device may be used with curved or pre-bentcatheters for delivery of a single optical fiber with or without a lensdevice for operatively, selectively and/or controllably directing laserenergy. Such devices can be easily manipulated to create dense injurypatterns and ultrasound ranging can be used to control the depth andselect depth. Additionally, piercing, analysis or other procedure can becarried out at an angle, thereby providing enhanced depth control.

The catheters of the present invention are especially suitable formedical procedures, including TMR, when operated in conjunction withoptical fiber laser delivery means. Such optical fibers or fiber bundlesutilize individual fibers from 25 to 1000 microns, or more or less. Byway of example only, and not limited to the following, typical cathetersof the present invention may have a diameter equivalent to between about5 and about 7 French in which fibers or fiber bundles between about 250and about 500 microns are used for laser energy delivery.

Laser firing can be controlled by any known or other specific means.Such control means include laser interlock with contact electrodes,distally mounted pressure transducer, etc. Pace control, or control ofthe laser as a function of the heart beat, can be implemented, includingsynchronous, asynchronous, or random pathway creation relative to theheart beat. Additionally, operator signals such as lights, audiblesignals, etc. may be used to facilitate and/or coordinate operation bythe cardiology operating room team. Suitable sensors may be mounted onthe distal-most tips or front faces of the devices, such as (but notlimited to) those shown in FIGS. 2, 4, 5, 6, 9 and 11.

Furthermore, smaller, more singular, generally lower power settingsdifferentiate or characterize systems used for laser assistedendocardial extension methods of the present invention from that oftypical TMR or PTMR procedures. By way of example, but not limited to inany way, typical power settings for a holmium laser might be 3.5 wattsfor a single pulse injury where such a single pulse injury is repeatedmultiple times to form a dense pattern of injuries greater than 1 mmapart.

It will be understood by the foregoing discussion that numerous meansfor creating the channels or zones of stimulation will be known to thoseskilled in the art, and are included within the scope of thisapplication. Mechanical means, include piercing, cutting, flushing,reaming, ultrasound and other devices and methods. Such will alsoinclude any adjunct structural enhancements, such as for visualization.Electromagnetic energy will also include radio frequency, laser energy,thermal energy, etc. Such means will be referred to hereafter,generally, as mechanical and thermoelectric energy functional devices.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described can be used in thepractice or testing of the present invention, the preferred methods andmaterials are now described. All publications and patent documentsreferenced in this application are incorporated herein by reference.

While the principles of the invention have been made clear inillustrative embodiments, there will be immediately obvious to thoseskilled in the art many modifications of structure, arrangement,proportions, the elements, materials, and components used in thepractice of the invention, and otherwise, which are particularly adaptedto specific environments and operative requirements without departingfrom those principles. The appended claims are intended to cover andembrace any and all such modifications, with the limits only of the truepurview, spirit and scope of the invention.

What is claimed is:
 1. A method of treating boundary areas in myocardiumwithin the left ventricle of the heart including the following steps:providing an apparatus having proximal and distal ends, at least onelumen therein, a steering mechanism operable from the proximal end andextending to the distal end, at least one treatment device having atreatment diameter substantially no greater than 1.0 mm slidablyextendable through the at least one lumen and through the distal endwherein one of said at least one treatment device is a mechanical devicehaving a first piercing tool, and a second piercing tool having apiercing diameter substantially no greater than 1.0 mm for creating apilot entry path for the at least one treatment device to reach aselected boundary area; placing the distal end of such apparatus on asurface of the heart; advancing the second piercing tool through thesurface a distance selected to reach the boundary area; advancing the atleast one treatment device through a pilot entry created by the secondpiercing tool until a distal end thereof reaches the boundary area; andoperating the at least one treatment device having the mechanical devicewith the first piercing tool to create a pattern of injury sites at theboundary area, the pattern having injuries no greater than 3.0 mm indiameter with each injury in the pattern spaced approximately no morethan 1 cm from each contiguous injury.
 2. The method of claim 1 whereina second of said at least one treatment device is a laser device and thestep of creating the pattern of injury sites is performed using laserenergy from the laser device.
 3. The method of claim 2 furthercomprising operating the laser at a power level of 3.5 watts andcreating each injury with a single pulse of energy delivered through afiber element having a diameter of 1 mm.
 4. The method of claim 3further comprising the step of delivering holmium laser energy throughthe fiber element to create each injury.
 5. The method of claim 2further comprising providing an excimer laser to deliver laser energythrough the fiber element.
 6. The method of claim 1 wherein the step ofadvancing the second piercing tool further comprises advancing thesecond piercing tool through endocardium to reach myocardium borderingthe endocardium, and the step of operating the at least one treatmentdevice to create a pattern of injury sites further comprises creatingsufficient injury sites to create a sinusoidal, spongy mesh ofinterconnecting passageways in the bordering myocardium for enhancingblood flow through the endocardium into the myocardium bordering thetreated myocardium.
 7. The method of claim 1 further comprisingproviding a radio frequency treatment device.
 8. A method of treatingboundary areas in myocardium within the left ventricle of the heartincluding the following steps: providing an apparatus having proximaland distal ends, at least on lumen therein, a steering mechanismoperable from the proximal end and extending to the distal end, at leasttwo treatment devices having a treatment diameter substantially nogreater than 1.0 mm slidably extendable through the at least one lumenand through the distal end, and a piercing tool having a piercingdiameter substantially no greater than 1.0 mm for creating a pilot entrypath for the at least one treatment device to reach a selected boundaryarea; placing the distal end of such apparatus on a surface of theheart; advancing the piercing tool through the surface a distanceselected to reach the boundary area; advancing the at least onetreatment device through a pilot entry created by the piercing tooluntil a distal end thereof reaches the boundary area; and operating theat least two treatment devices simultaneously to create a pattern ofinjury sites at the boundary area, the pattern having injuries nogreater than 3.0 mm in diameter with each injury in the pattern spacedapproximately no more than 1 cm from each contiguous injury.
 9. Themethod of claim 8 further comprising the step of spreading distal tipsof the at least two treatment devices apart to form treatment endsdeflected approximately 1 to 45 degrees relative to a central axis ofthe apparatus.
 10. A method of treating boundary areas in myocardiumwithin the left ventricle of the heart including the following steps:providing an apparatus having proximal and distal ends, at least onlumen therein, a steering mechanism operable from the proximal end andextending to the distal end, at least one treatment device having atreatment diameter substantially no greater than 1.0 mm slidablyextendable through the at least one lumen and through the distal end, apressure transducer at the distal end, and a piercing tool having apiercing diameter substantially no greater than 1.0 mm for creating apilot entry path for the at least one treatment device to reach aselected boundary area; placing the distal end of such apparatus on asurface of the heart; advancing the piercing tool through the surface adistance selected to reach the boundary area; advancing the at least onetreatment device through a pilot entry created by the piercing tooluntil a distal end thereof reaches the boundary area; operating thetreatment device to create a pattern of injury sites at the boundaryarea, the pattern having injuries no greater than 3.0 mm in diameterwith each injury in the pattern spaced approximately no more than 1 cmfrom each contiguous injury; and monitoring pressure at the myocardiumwith said pressure transducer to control timing of treatment.